On Mar 20, 2006, at 2:28 PM, rtilley wrote:
> I wish to write one method to work with all classes in Digest::Base  
> without repeatedly writing the same code.

How about this:

$ cat digest.rb
require 'digest/md5'
require 'digest/sha1'
require 'digest/sha2'
require 'digest/rmd160'

def hash_file(file, hash_kind)
   digest = Digest.const_get(hash_kind.to_s.upcase).new
   open(file, 'rb') do |f|
     while (chunk = f.read(1))
       digest.update(chunk)
     end
   end
   digest
end

puts "RMD160: #{hash_file(__FILE__, :rmd160)}"
puts "MD5:    #{hash_file(__FILE__, :md5)}"
puts "SHA1:   #{hash_file(__FILE__, :sha1)}"
puts "SHA256: #{hash_file(__FILE__, :sha256)}"

$ ruby digest.rb
RMD160: a99c2c1919b289412a98dc4562598d904e2a5750
MD5:    0a35b2d64cc5201314b691f3c8588ac6
SHA1:   f47b890ec66801e1f24956214d8a6f13c7f8daac
SHA256: bda670c53c5ff548a88f274ce17493adc0c229e32c221990e0c779c881425886

-- Daniel